Current investigations are directed towards devising methods for the separation of the mixtures of specific dextransucrases produced in liquid culture by cariogenic and non-cariogenic Streptococcus mutants. Use is being made of the high affinity of the component enzymes for dextrans of different structure and separations are being made on affinity chromatography columns containing insoluble dextrans mixed with Biogel P2 or columns containing dextrans covalently bound to Sepharose B4. The properties and specificities of the separated enzymes are being studied with respect to their roles in the synthesis of insoluble, plaque forming dextrans and a means of inhibiting the purified enzymes in a highly specific manner in vitro is being sought. The specific inhibition of one or more of these enzymes may prove effective in decreasing the incidence of dental caries in vivo. Bibliographic references: The role of the 1,6-alpha-glucosidic bond in the synthesis of alpha-glucans. J. Carter, M.M. McCabe and E.E. Smith. Biochem. Soc. Trans. 3, (1975) 75-76.